YTM ≈ [C + (F−P)/n] / [(F+P)/2]。
YTM ≈ [C + (F−P)/n] / [(F+P)/2]。
| Item | Formula / Rule | Source / Standard |
|---|---|---|
| Approximation | YTM ≈ [annual coupon + (face − price)/years] / [(face + price)/2] | Fabozzi 2021, Bond Markets, Analysis and Strategies, Ch. 3 |
| Error source | The average-price denominator replaces discounted cash flows, so error grows with maturity and discount depth | Fabozzi 2021, Bond Markets, Analysis and Strategies, Ch. 3 |
| Exact solution | Exact YTM requires numerically solving the present-value equation, typically by Newton iteration | Hull 2022, Options, Futures and Other Derivatives, Ch. 4 |